1. Field of the Invention
The present invention relates to a fragrant non-hollow core-in-sheath type composite staple fiber and a gradual fragrance-emitting textile material containing same. More particularly, the present invention relates to a fragrant non-hollow core-in-sheath type composite staple fiber in which a non-hollow core portion thereof contains an essential oil and is covered by a sheath portion, and accordingly, a fragrance is gradually emitted through cut end faces of the core portion over a long time, and which provides an atmosphere reminiscent of a forest and has a refreshing effect, and a gradual fragrance-emitting textile material containing same.
2. Description of the Related Arts
Hinoki wood (timber) has been used to form pillars or the flooring of a house, and the specific fragrance of the Hinoki wood has a calming effect on people living in the house and provides an atmosphere reminiscent of a forest within the house. Nevertheless, the effect of the fragrant substance in the Hinoki wood becomes weaker with an elapse of time, and thus it is difficult to maintain the fragrant effect thereof at a satisfactory level for a long time.
Accordingly, various attempts have been made to obtain the atmosphere of a forest in a house, by applying an essence of natural essential oils to bedclothes, furnishings, and interior materials. For example, attempts have been made to adhere an essential oil to clothes or to cause the essential oil to be adsorbed by clothes, by a finishing process. This attempt is disadvantageous, however, in that the essential oil is easily removed from the clothes by water-rinsing or laundering, or due to a rapid vaporization thereof, and thus the durability of the fragrant effect is unsatisfactory.
Japanese Unexamined Patent Publication No. 61-201012 discloses a hollow core-in-sheath type composite fiber in which a member selected from natural essential oils, and fragrant essences extracted from the oils, is contained in the core portion thereof. Also, Japanese Unexamined Patent Publication No. 62-85010 discloses a hollow multiple cores-in-sheath type composite fiber in which the fragrant substance is contained in the multiple core portions.
The above-mentioned conventional hollow composite fibers, however, have an unsatisfactory durability of the fragrant effect thereof. Also, the hollow composite fibers are disadvantageous in that, since each core portion composed of an olefin polymer has a filamentary hollow extending along the longitudinal axis of the fiber, when a pressure is applied to the peripheries of the hollow composite fibers, the hollow composite fibers are flattened by squeezing the hollows, and thus exhibit a reduced bulkiness. Accordingly, when the hollow composite fibers are used as a wadding material for a mattress, pillow, cushion or stuffed toy, which are frequently compressed under a high compressive load, the bulkiness or elastic resistance to compression of the resultant material is difficult to maintain at a satisfactory level for a long time. In other attempts, Japanese Unexamined Patent Publication Nos. 1-260,066 and 1-266,201 disclose a fiber product having microcapsules containing therein a fragrant substance and adhered to a surface thereof through a binder material, and Japanese Unexamined Patent Publication No. 1-280068 discloses a composite fiber in which a fragrant substance-containing polymer is coated on an exposed outer surface portion thereof.
The fragrant microcapsule-containing fiber product is disadvantageous in that the fragrant microcapsules are easily removed from the fiber product surface, and thus the durability of the fragrant effect is unsatisfactory.
The composite fiber coated by the fragrant substance-containing polymer has a relatively large surface area in which the fragrant substance is located, and thus exhibits a very high fragrant effect at an initial stage of use. Nevertheless, this type of composite fiber is disadvantageous in that the strength of the fragrant substance is rapidly lowered due to a vaporization thereof on the large surface area of the fiber, and thus the durability of the fragrant effect is unsatisfactory.